/* Mednafen - Multi-system Emulator
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "../mednafen.h"
#include "escape.h"

static unsigned int hex_nibble_to_val(char nibble)
{
  unsigned int ret = 0;
  nibble = tolower(nibble);

  if(nibble >= '0' && nibble <= '9')
    ret = nibble - '0';
  else
    ret = nibble - 'a';

  return(ret);
}

void unescape_string(char *string)
{
  char *src = string;
  bool inescape = 0;
  uint8 hoval = 0;
  int inhex = 0;
  int inoctal = 0;

  while(*src)
  {
    if(*src == '\\')
    {
      inescape = TRUE;
      inhex = 0;
      inoctal = 0;
    }
    else if(inhex)
    {
      if(inhex == 1) 
      {
        hoval = hex_nibble_to_val(*src) << 4;
        inhex++;
      }
      else if(inhex == 2)
      {
        hoval |= hex_nibble_to_val(*src);
        *string = hoval;
        string++;
        hoval = 0;
        inhex = 0;
      }
    }
    else if(inoctal)
    {
      if(inoctal == 1)
      {
        hoval = (*src - '0') * 8 * 8;
      }
      else if(inoctal == 2)
      {
        hoval += (*src - '0') * 8;
      }
      else
      {
        hoval += *src - '0';
        *string = hoval;
        string++;
        hoval = 0;
        inoctal = 0;
      }
    }
    else if(inescape)
    {
      switch(*src)
      {
      case 'a': *string = 7; string++; break;
      case 'b': *string = 8; string++; break;
      case 'f': *string = 12; string++; break;
      case 'n': *string = 10; string++; break;
      case 'r': *string = 13; string++; break;
      case 't': *string = 9; string++; break;
      case 'v': *string = 11; string++; break;

      case '\\': *string = '\\'; string++; break;
      case '?': *string = '?'; string++; break;
      case '\'': *string = '\''; string++; break;
      case '"': *string = '"'; string++; break;

      case 'o': inoctal = 1; break;
      case 'x': inhex = 1; break;


      default: *string = *src; string++; break;
      }
      inescape = 0;
    }
    else
    {
      *string = *src;
      string++;
    }
    src++;
  }
  *string = 0;
}

char *escape_string(const char *text)
{
  uint32 slen = strlen(text);
  char *ret = (char*)malloc(slen * 4 + 1); // \xFF
  char *outoo = ret;

  for(uint32 x = 0; x < slen; x++)
  {
    int c = (uint8)text[x];

    if(c < 0x20 || c == 0x7F || c == '\\' || c == '\'' || c == '"')
    {
      *outoo++ = '\\';

      switch(c)
      {
      case '\\': *outoo++ = '\\'; break;
      case '\'': *outoo++ = '\''; break;
      case '"': *outoo++ = '"'; break;
      case 7: *outoo++ = 'a'; break;
      case 8: *outoo++ = 'b'; break;
      case 12: *outoo++ = 'f'; break;
      case 10: *outoo++ = 'n'; break;
      case 13: *outoo++ = 'r'; break;
      case 9: *outoo++ = 't'; break;
      case 11: *outoo++ = 'v'; break;

      default: outoo += sprintf(outoo, "x%02x", c); break;
      }
    }
    else
      *outoo++ = c;
  }

  *outoo = 0;

  return(ret);
}
